In the 3rd Generation Partnership Project (3GPP), a radio access method and a radio network for cellular mobile communications (hereinafter, referred to as “Long Term Evolution (LTE)”, or “Evolved Universal Terrestrial Radio Access (EUTRA)”) have been studied. In LTE, a base station apparatus is also referred to as an evolved NodeB (eNodeB), and a terminal apparatus is also referred to as a User Equipment (UE). LTE is a cellular communication system in which multiple areas each covered by the base station apparatus are deployed to form a cellular structure.
LTE supports a Time Division Duplex (TDD). LTE that employs the TDD scheme is also referred to as TD-LTE or LTE TDD. In TDD, uplink signals and downlink signals are time division multiplexed. Also, LTE supports a Frequency Division Duplex (FDD).
In 3GPP, a configuration where a terminal apparatus simultaneously performs transmission and/or reception on more than five serving cells (component carriers) has been considered. Furthermore, a configuration where a terminal apparatus transmits a physical uplink control channel on a secondary cell which is a serving cell other than the primary cell has been considered (NPL 1).